Thank you ITR HEAT (OASIS) - YAPF!

[Neal]

Yet Another Pump Failure
​

Upon returning from my Freightliner service visit I setup the heat for in storage. I noticed the rear zone (zone 2) wasn't heating. After a few trips to storage to check things out, fuses all checked good, replaced and swapped them, did everything I could to figure this one out. NO red lights, no zone failure indicators, no blown fuses.

Today I went to the coach in storage and pulled the pump panel off and beat ever metal pipe and connection but a check valve issue didn't make sense as zone 1 and hot water (cough: summer loop - the pump with a stupid name) all worked. Zone 2 was the first pump to go bad and was replaced about a year ago I believe with a ITR OASIS "smooth" replacement pump I ordered around 2021 (ordered two). I put my hand on it and it felt like it was running/vibrating, hard to tell.

I noticed the zone 1 pump wiring was flaky, the pump would go on/off as the connectors moved, that will need to be addressed later but I disconnected/reconnected those. In fact, all of those wires should be secured so they cannot vibrate or move while the coach (aka earthquake) is underway.

So I went in and grabbed one of my brand new ITR OASIS supplied pumps I just received with solid gold interior parts costing $250/ea and replaced Zone 2 again. Yep, it works now. It was odd that when disconnecting the two hoses the fluid was under pressure. While I was wearing gloves I was not wearing safety glasses so I put my hand over it to prevent getting hit in the face with spraying fluid. Question is why was it under pressure? Yes, I just turned the system off, but odd nonetheless. That was a little concerning but it seems to me the "smooth" pump, i.e. rebranded and over priced US Solar pump was not putting out sufficient pressure to move the fluid?? I'm keeping the pump, I may try it in the next pump failure which will probably be zone 1, it's the lone survivor original pump in the system now.

So yeah, one year old pump, maybe, replaced. Pretty sad how unreliable this OASIS hydronic heating system is and how much pain all of us coach owners have to deal with this design and constant failures.

Edit: found my old post, prior zone 2 failure mid 2021

 

[Rich W.]

​

Pretty sad how unreliable this OASIS hydronic heating system is and how much pain all of us coach owners have to deal with this design and constant failures.​

…not to mention the cost of the system as an option in the first place! It makes a pretty good argument for a propane furnace and water heater.

 

[osuallen]

Question is why was it under pressure? Yes, I just turned the system off, but odd nonetheless.

Just like with your engine radiator fluid, it wants to expand as it heats up. Since it is a closed system, the ability to expand is limited and results in a build up of pressure.

 

[Kevin D Pem]

Just like with your engine radiator fluid, it wants to expand as it heats up. Since it is a closed system, the ability to expand is limited and results in a build up of pressure.

I buy that! So what happens to a small power pump that is fighting excessive head pressure?

Just a thought!

 

[MemoriesByTheMile]

I wonder why some installations seem to have problems with failing pumps every year (or so) but others don’t have any issues. (Knock on wood…)

 

[Neal]

I went about 5 years without an issue. Maybe the older pumps were better. Zone 2 twice now (2021/2023), summer loop just went (2023), zone 1 still going.

 

[osuallen]

I buy that! So what happens to a small power pump that is fighting excessive head pressure?

Just a thought!

The pressure from the fluid expansion is uniform throughout the system and the pressure itself does not affect the friction based pressure that will affect the flow vs head output of the pump. The only effect it has is that to build the overall system pressure, the fluid is hotter and therefore somewhat less viscous, but in the case of the oasis, that is a pretty minor difference (and actually lowers the friction).

 

[Kevin D Pem]

The pressure from the fluid expansion is uniform throughout the system and the pressure itself does not affect the friction based pressure that will affect the flow vs head output of the pump. The only effect it has is that to build the overall system pressure, the fluid is hotter and therefore somewhat less viscous, but in the case of the oasis, that is a pretty minor difference (and actually lowers the friction).

Like I said, only a thought. So no back flow valves or anything, that's good

 

[Roadglide117]

do you put teflon tape on the US Solar pump that require a brass nipple to be screwed on to the pump?